The present invention is in the field of missile fin control. More specifically this invention relates to an apparatus and method for locking and unlocking missile control fins.
Flight control systems for a missile generally comprise fins which are moveable and controllable during flight. When these missiles are carried on the exterior of an aircraft, the missile, and thus the fins, are subjected to high aerodynamic loading. This loading can cause the fins to move and flutter, which in turn puts loads on the fin control mechanism, potentially causing failure or fatigue. Any fatigue or failure may result in the missile not being controlled accurately enough to reach its target.
Prior methods have provided locks to keep the fins from moving prior to launch. Most of these methods call for the locking of the fins by insertion of some type of locking mechanism into the fin, and removal of this mechanism before launching. For example, U.S. Pat. No. 6,352,217 provides for a slot in each fin wherein a locking pin is inserted into this slot. This pin is then connected by a linkage to a slide mechanism. There is a striker which is activated to strike this slide member, thus initiating movement, which in turn hopefully will move the linkage, which in turn will retract the locking pin. This is typical of the prior art which has complicated mechanism which depend on each other working to produce the desired result and which must initiate positive movement to unlock the missile fins. The more complicated the mechanism, the more chances there are for error. Further, having to initiate positive movement requires overcoming inertia, which is another chance for an error or malfunction. A missile fin locking mechanism is desired which would not require such complicated mechanism, and which would not require the initiation of positive movement to unlock the fins.
Prior locking methods such as the one described above, do not allow for testing of the mechanism after installation. Typically the missile is assembled in the “fin-locked” position, and is maintained that way until the missile is fired. A fin locking method and apparatus is desired which would allowed the missile to be assembled, the fins locked, the unlocking of the fins tested, and then the fins re-locked.
Further, prior fin-locking mechanisms have been assembled with the assembly of the missile. This process is time consuming and often complicated. A fin locking apparatus is desired which could be pre-assembled, and then placed into a missile during assembly, this would reduce the time, complexity, and cost of this process.